what us the difference of partition 1 and current in disk utility?

Hi everyone,

I bought a WD my passport slim , wanna use half for timemachine n half for file storage, but now only wanna for TM.

I formated it by the erase function in disk utility, n then I click the Inbutton, n it show that partition is zero, why? Since there has one partition why it show zero?

But in the partition tab, it showed "current" n there has 1 partition and more to choose from, I wondering what is the difference between "current" and 1 partition , what I should do before I make the whole hard drive for TM, if I make one partition for TM n other for file storage will my hard drive become unstable?

BTW, if I select the drive, the partition an remain but if I choose the partition of drive ,the partition tab disappear does this normal?

And also if I format the hard dive to hfs+ encrypted the RAID, erase restore tab will disappear too in disk utility, does this normal too?